Vascular plant inventory of Ka'āpahu, Haleakalā National Park

Abstract

Between 2002 and 2004, a vegetation survey was completed to document vascular plant species within the 598-ha (1,478-acre) parcel of Ka'āpahu, Haleakalā National Park. The results of this inventory provide a checklist for the area. Observations in this and previous surveys document two hundred and ninety-two vascular plant species in Ka'āpahu. Of all the taxa that have been documented, 157 (54%) are native, of which 110 are endemic and 47 are indigenous to the Hawaiian Islands. One hundred and thirty-five (46%) are nonnative species, of which twelve species are Polynesian introductions. Two botanists surveyed routes within the Ka'āpahu parcel for species not found on the park checklist as well as federally listed and rare native species. Data were collected on the target species and the sites in which they were found. Two hundred and eighty-seven species were seen during this survey, resulting in the addition of eight species to the park checklist. Two of these are endemic and six are non-native species, one of which is a Polynesian introduction. Seven populations of four species listed as endangered by the U.S. Fish and Wildlife Service (USFWS) were found. Six populations of three species listed as candidates for endangered status by the USFWS were found. One population of a species listed by the USFWS as a species of concern (SOC) was recorded. Twenty-eight populations of 10 species rare to the park were documented. Based on site information, surveyors categorized vegetation types into five elevation zones.